I've been trying to think of other nationalities for which there isn't a "+ s" plural:

The Japanese, the Chinese, the Dutch (remember that their country is "The Netherlands", and not "Holland", which was a province of the country now split into North Holland and South Holland).

.....quite a few more I reckon.

Spanish people can be referred to as Spaniards.

A little tricky is how to refer to Scottish people. "Scotch" is used to describe their whisky. Some say "the Scots", and "a Scotsman" is often used when referring to an individual. But, in this case, how would a woman feel on hearing this to describe her?

I understand that the adjective "Scottish" should be used when referring to products made in Scotland, for example.

I'm not a Scot, so check around for more information if you want to be absolutely certain how to go about this.

A related subject concerns the words used for a person's city of origin. I love them - they are very colourful! They can be nouns and adjectives. Here are a few:

Manchester - a Mancunian, often shortened to "a Manc", both with a hard "c";